"What are birth control pills and how do they work?
Birth control pills are also known as oral contraceptives (OCs) or, simply, “the pill.” They offer protection against pregnancy by blocking the union of sperm and egg, thereby prevent"...
An increased risk of the following serious adverse reactions has been associated with the use of oral contraceptives (See WARNINGS):
- Thrombophlebitis and thrombosis
- Arterial thromboembolism
- Pulmonary embolism
- Myocardial infarction and coronary thrombosis
- Cerebral hemorrhage
- Cerebral thrombosis
- Gallbladder disease
- Benign and malignant liver tumors, and other hepatic lesions
There is evidence of an association between the following conditions and the use of oral contraceptives, although additional confirmatory studies are needed:
- Mesenteric thrombosis
- Neuro-ocular lesions (e.g., retinal thrombosis and optic neuritis)
The following adverse reactions have been reported in patients receiving oral contraceptives and are believed to be drug-related:
- Gastrointestinal symptoms (such as abdominal cramps and bloating)
- Breakthrough bleeding
- Change in menstrual flow
- Amenorrhea during or after use
- Temporary infertility after discontinuation of use
- Chloasma or melasma, which may persist
- Breast changes: tenderness, enlargement, secretion
- Change in weight (increase or decrease)
- Change in cervical erosion or secretion
- Diminution in lactation when given immediately postpartum
- Cholestatic jaundice
- Rash (allergic)
- Mental depression
- Reduced tolerance to carbohydrates
- Vaginal candidiasis
- Change in corneal curvature (steepening)
- Intolerance to contact lenses
The following adverse reactions or conditions have been reported in users of oral contraceptives and the association has been neither confirmed nor refuted:
- Premenstrual syndrome
- Changes in appetite
- Cystitis-like syndrome
- Loss of scalp hair
- Erythema multiforme
- Erythema nodosum
- Hemorrhagic eruption
- Impaired renal function
- Hemolytic uremic syndrome
- Changes in libido
- Budd-Chiari syndrome
- Endocervical hyperplasia or ectropion
Read the Zovia (ehtynodiol diacetate and ethinyl estradiol tablets) Side Effects Center for a complete guide to possible side effects »
Reduced efficacy and increased incidence of breakthrough bleeding and menstrual irregularities have been associated with concomitant use of rifampin. A similar association, though less marked, has been suggested for barbiturates, phenylbutazone, phenytoin sodium, and possibly with griseofulvin, ampicillin, and tetracyclines. Administration of troglitazone concomitantly with a combination oral contraceptive (estrogen and progestin) reduced the plasma concentrations of both hormones by approximately 30%. This could result in loss of contraceptive efficacy.
Laboratory test interactions
Certain endocrine and liver function tests and blood components may be affected by oral contraceptives:
- Increased prothrombin and factors VII, VIII, IX and X; decreased antithrombin III; increased platelet aggregability.
- Increased thyroid binding globulin (TBG), leading to increased circulating total thyroid hormone as measured by proteinbound iodine (PBI), T4 by column or by radioimmunoassay. Free T3 resin uptake is decreased, reflecting the elevated TBG; free T4 concentration is unaltered.
- Other binding proteins may be elevated in the serum.
- Sex-steroid binding globulins are increased and result in elevated levels of total circulating sex steroids and corticoids; however, free or biologically active levels remain unchanged.
- Triglycerides and phospholipids may be increased.
- Glucose tolerance may be decreased.
- Serum folate levels may be depressed. This may be of clinical significance if a woman becomes pregnant shortly after discontinuing oral contraceptives.
- Increased sulfobromophthalein and other abnormalities in liver function tests may occur.
- Plasma levels of trace minerals may be altered.
- Response to the metyrapone test may be reduced.
Last reviewed on RxList: 12/17/2008
This monograph has been modified to include the generic and brand name in many instances.
Additional Zovia Information
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